Figure 3
From: New approach to detect seismic surface waves in 1Hz-sampled GPS time series
Skyview plot of the satellites above the sites 0051, 0222, 0292, MIZU and TSKB at the time of the seismic waves passage.
The satellite configuration is not optimal because the number of satellites is limited along the axis N0/N180. Although, this lack of satellites is not due to a satellite tracking issue, because the position of satellite vary little from site to site (over 300 km distance). All sites will have poor accuracy on the north component of the vibration as there are very few sites in the quadrants N135-N225 and N315-N45
